No abstract

Thymoquinone (TQ) is the main active constituent of Nigella sativa seeds. The objective of this study was to explore the protective effects of TQ on diazinon (DZN)-induced liver toxicity in the mouse model. The animals were divided into five groups of 6 each and treated intraperitoneally. Group 1 received the vehicle, group 2 was given 16 mg/kg DZN, group 3 received 5 mg/kg TQ, and groups 4 and 5 were treated with 1.25 and 5 mg/kg of TQ as well as 16 mg/kg DZN, respectively. Finally, butyrylcholinesterase (BChE), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) serum activity as well as nitric oxide (NO), lipid peroxidation (LPO), total antioxidant capacity (TAC), total thiol molecule (TTM), and histopathological experiments were evaluated in the liver samples. Our findings showed that DZN caused a significant increase in ALT (P < 0.01), AST (P < 0.001), ALP (P < 0.001) serum levels, LPO (P < 0.001) and NO (P < 0.001), the depletion of the TAC (P < 0.05) and TTM (P < 0.001), and structural changes in the liver tissue. Following TQ administration, a significant improvement was observed in the oxidative stress biomarkers in the liver tissue. In addition, our biochemical findings were correlated well to the histopathological examinations. In conclusion, the data from this study indicate that the administration of TQ may prevent liver damage by preventing free radical formation in animals exposed to DZN.

Abstract:Urtica dioica or stinging nettle is traditionally used as an herbal medicine in Western Asia. The current study represents the investigation of antimicrobial activity of U. dioica from nine crude extracts that were prepared using different organic solvents, obtained from two extraction methods: the Soxhlet extractor (Method I), which included the use of four solvents with ethyl acetate and hexane, or the sequential partitions (Method II) with a five solvent system (butanol). The antibacterial and antifungal activities of crude extracts were tested against 28 bacteria, three yeast strains and seven fungal isolates by the disc diffusion and broth dilution methods. Amoxicillin was used as positive control for bacteria strains, vancomycin for Streptococcus sp., miconazole nitrate (30µg/mL) as positive control for fungi and yeast, and pure methanol (v/v) as negative control. The disc diffusion assay was used to determine the sensitivity of the samples, whilst the broth dilution method was used for the determination of the minimal inhibition concentration (MIC). The ethyl acetate and hexane extract from extraction method I (EA I and HE I) exhibited highest inhibition against some pathogenic bacteria such as Bacillus cereus, MRSA and Vibrio parahaemolyticus. A selection of extracts that showed some activity was further tested for the MIC and minimal bactericidal concentrations (MBC). MIC values of Bacillus subtilis and Methicillin-resistant Staphylococcus aureus (MRSA) using butanol extract of extraction method II (BE II) were 8.33 and 16.33mg/mL, respectively; while the MIC value using ethyl acetate extract of extraction method II (EAE II) for Vibrio parahaemolyticus was 0.13mg/mL. Our study showed that 47.06% of extracts inhibited Gram-negative (8 out of 17), and 63.63% of extracts also inhibited Gram-positive bacteria (7 out of 11); besides, statistically the frequency of antimicrobial activity was 13.45% (35 out of 342) which in this among 21.71% belongs to antimicrobial activity extracts from extraction method I (33 out of 152 of crude extracts) and 6.82% from extraction method II (13 out of 190 of crude extracts). However, crude extracts from method I exhibited better antimicrobial activity against the Gram-positive bacteria than the Gram-negative bacteria. The positive results on medicinal plants screening for antibacterial activity constitutes primary information for further phytochemical and pharmacological studies. Therefore, the extracts could be suitable as antimicrobial agents in pharmaceutical and food industry. Rev. Biol. Trop. 60 (4): 1567-1576. Epub 2012 December 01.

Phytochemical screening assay on crude extracts of Ocimum tenuiflorum L. leaves and methanol fractions was performed in this study. Phytochemical qualitative assay on aqueous crude extract and aqueous fraction did not show any steroid and terpenoid. However, ethanol and butanol fractions also did not show steroid in the screening test. The result of HPLC identification of active crude extracts and active fractions showed the possible bioactive compounds in this plant extracts, which may control diabetes. These findings showed that the active crude extract (methanol) and its active fractions (ethyl acetate, and butanol) showed the presence of polyphenolic active constituents such as 3,4-dimethoxycinnamic acid, caffeic acid, diosmetin, luteolin, kaempferol, rosmarinic acid, apigenin, and genistein that control the blood glucose in diabetic rats. Furthermore, isolation of the active components may pave the way for the development of new agents for the treatment of diabetes and its complications.

Oxidative stress (OS) is a main mechanism in organophosphorus poisoning. The effects of calcium channel blockers have been confirmed in decreasing of oxidative stress. In the current study, the effects of amlodipine (AM), as a calcium channel blocker, were evaluated on oxidative damages induced by diazinon (DZN) in hippocampus tissue of Wistar rats. Forty-two rats were divided into six groups and treated intraperitoneally for two weeks. Group 1 served as control received vehicle, group 2 was treated with 9 mg/kg of AM, group 3 (positive control) received DZN (32 mg/kg), Groups 4, 5, and 6 were treated with 3, 6, and 9 mg/kg of AM adjunct with DZN (32 mg/kg), respectively. After 14 days, all the animals were sacrificed under anesthesia and hippocampus tissue and blood samples were collected for biochemical analysis and histopathology experiments. The results showed that DZN caused significant increase in lipid peroxidation (P < 0.001), nitric oxide (P < 0.001) and lactate dehydrogenase (P < 0.001) levels, depletion of total antioxidant capacity (P < 0.01), and structural changes in hippocampus tissues. Following AM administration, a significant improvement was observed in oxidative biomarkers in hippocampus tissues. Additionally, our biochemical findings were related well with histopathological examinations. In conclusion, the data of this study indicated that AM administration may prevent oxidative damages via improving of energy production and preventing of free radical formation in DZN-exposed animals.